1. Introduction to Cells AP Biology

2. The Miller-Urey Experiment

3. Origins of Life Panspermia is the hypothesis that "seeds" of life exist already all over the Universe, that life on Earth may have originated through these "seeds", and that they may deliver or have delivered life to other habitable bodies. The RNA world hypothesis proposes that a world filled with life based on ribonucleic acid (RNA) predates the current world of life based on deoxyribonucleic acid (DNA). RNA, which can both store information like DNA and act as an enzyme, may have supported cellular or pre-cellular life. Some hypotheses as to the origin of life present RNA-based catalysis and information storage as the first step in the evolution of cellular life.

4. All organisms share fundamental properties Cellular organization- all organisms consist of one or more cells- complex, organized assemblages of molecules enclosed within membranes Sensitivity- all organisms respond to stimuli-though not always to the same stimuli in the same ways Growth- All living things assimilate energy and use it to maintain order and grow, a process called metabolism. Development- Both unicellular and multicellular organisms organisms undergo systematic, gene-directed changes as they grow and mature. Reproduction- Organisms reproduce, passing on genes from one generation to the next. Regulation- All organisms have regulatory mechanisms that coordinate internal processes. Homeostasis- All living things maintain relatively constant internal conditions, different from their environment. Heredity- All organisms on Earth posses a genetic system that is based on the replication of a long, complex molecule called DNA. This mechanism allows for adaptation and evolution over time and is a distinguishing characteristic of living organisms.

5. Compartmentalization

8. Figure 6.4 Electron micrographs Transmission Electron MicroscopyScanning Electron Microscopy

9. Prokaryotes vs. Eukaryotes Prokaryotes –Bacteria and cyanobacteria –1-10  m –Few or no organelles –Circular DNA –No cytoskeleton or cytoplasmic streaming –Chromosomes segregate by attachments to plasma membrane –Mainly unicellular Eukaryotes –Protists, fungi, plants and animals –5-100  m –Organelles –Long linear DNA –Cytoskeleton and cytoplasmic streaming –Chromosomes segregate by cytoskeletal spindle apparatus –Often multicellular

14. The nucleus and its envelope Nuclei and actin

15. The Nucleus

16. Nuclear Pore Complex

17. The Smooth and Rough ER (sER and rER)

18. Origin of Nucleus and Endoplasmic Reticulum

19. Ribosomes

20. The signal mechanism for targeting proteins to the ER All translation starts in the cytoplasmAll translation starts in the cytoplasm Signal sequence directs destinationSignal sequence directs destination

21. The Golgi Apparatus

22. Modification of Proteins by the Golgi Apparatus

23. Movement through the Golgi http://www.youtube.com/watch?v=rvfvRgk0MfA

24. Lysosomes

25. The formation and functions of lysosomes (Layer 1)

26. The formation and functions of lysosomes (Layer 2)

27. The formation and functions of lysosomes (Layer 3)

28. Review: relationships among organelles of the endomembrane system

29. Membrane orientation applies both to the lipid bilayer and transmembrane proteins Vesicle budding and fusion during vesicular transport

30. The plant cell vacuole

31. The mitochondrion, site of cellular respiration

32. The chloroplast, site of photosynthesis

33. Origin of Mitochondria

34. You are here You were here

35. Peroxisomes

36. The cytoskeleton

37. Cytoskeletal elements

38. The structure and function of the cytoskeleton

39. Motor proteins and the cytoskeleton

40. Centrosome containing a pair of centrioles Microtubules

41. Movement of Cells

42. A comparison of the beating of flagella and cilia Microtubules

43. Ultrastructure of a eukaryotic flagellum or cilium Microtubules

44. How dynein “walking” moves cilia and flagella

45. A structural role of microfilaments Actin

46. Microfilaments and motility

47. Actin

48. Plant cell walls Cell surfaces and junctions

49. Intercellular junctions in animal tissues Cell surfaces and junctions

50. Extracellular matrix (ECM) of an animal cell